Acetylcysteine

Description

11 DESCRIPTION Acetylcysteine injection is an intravenous antidote for the treatment of acetaminophen overdose. Acetylcysteine is the nonproprietary name for the N-acetyl derivative of the naturally occurring amino acid, L-cysteine (N-acetyl-L-cysteine, NAC). The compound is a white crystalline powder, which melts in the range of 104° to 110°C and has a very slight odor. The molecular formula of the compound is C 5 H 9 NO 3 S, and its molecular weight is 163.2. Acetylcysteine has the following structural formula: Acetylcysteine Injection is supplied as a sterile solution in vials containing 20% w/v (200 mg/mL) acetylcysteine. The pH of the solution ranges from 6.0 to 7.5. Acetylcysteine Injection contains the following inactive ingredients: 0.5 mg/mL disodium edetate, sodium hydroxide (used for pH adjustment), and water for injection, USP. Figure 3

What Is Acetylcysteine Used For?

1 INDICATIONS AND USAGE Acetylcysteine Injection is an antidote for acetaminophen overdose indicated to prevent or lessen hepatic injury after ingestion of a potentially hepatotoxic quantity of acetaminophen. Overdose incidences are divided into two types; Acute Ingestion or Repeated Supratherapeutic Ingestion (RSI). [see Dosage and Administration ( 2 ) and Acetaminophen Assays – Interpretation and Methodology -(Acute or Repeated Supratherapeutic Ingestion) ( 1.1 , 1.2 )] . On admission for suspected acetaminophen overdose, a serum blood sample should be drawn at least 4 hours after ingestion to determine the acetaminophen level and will serve as a basis for determining the need for treatment with acetylcysteine. If the patient presents after 4 hours post-ingestion, the serum acetaminophen sample should be determined immediately. Acetylcysteine Injection should be administered within 8 hours from acetaminophen ingestion for maximal protection against hepatic injury for patients whose serum acetaminophen levels fall above the "possible" toxicity line on the Rumack-Matthew nomogram (line connecting 150 mcg/mL at 4 hours with 37.5 mcg/mL at 12 hours); [see Acetaminophen Assays – Interpretation and Methodology (1.1, 1.2 )] . If the time of ingestion is unknown, or the serum acetaminophen level is not available, cannot be interpreted, or is not available within the 8 hour time interval from acetaminophen ingestion, Acetylcysteine Injection should be administered immediately if 24 hours or less have elapsed from the reported time of ingestion of an overdose of acetaminophen, regardless of the quantity reported to have been ingested. The aspartate aminotransferase (AST, SGOT), alanine aminotranferase (ALT, SGPT), bilirubin, prothrombin time, creatinine, blood urea nitrogen (BUN), blood glucose, and electrolytes also should be determined in order to monitor hepatic and renal function and electrolyte and fluid balance. NOTE: The critical ingestion-treatment interval for maximal protection against severe hepatic injury is between 0 to 8 hours. Efficacy diminishes progressively after 8 hours and treatment initiation between 15 and 24 hours post-ingestion of acetaminophen yields limited efficacy. However, it does not appear to worsen the condition of patients and it should not be withheld, since the reported time of ingestion may not be correct. Acetylcysteine Injection is an antidote for acetaminophen overdose indicated to prevent or lessen hepatic injury after ingestion of a potentially hepatotoxic quantity of acetaminophen (1) 1.1 Acetaminophen Assays Interpretation and Methodology – Acute Ingestion The acute ingestion of acetaminophen in quantities of 150 mg/kg or greater may result in hepatic toxicity. However, the reported history of the quantity of a drug ingested as an overdose is often inaccurate and is not a reliable guide to therapy of the overdose. Therefore, plasma or serum acetaminophen concentrations, determined as early as possible, but no...

Dosage and Administration

2 DOSAGE AND ADMINISTRATION The total dose of Acetylcysteine Injection is 300 mg/kg given as 3 separate doses and administered over a total of 21 hours. Please refer to the guidelines below for dose preparation based upon patient weight. The total volume administered should be adjusted for patients less than 40 kg and for those requiring fluid restriction (see Tables 1 and 2). The total dose of Acetylcysteine Injection is 300 mg/kg given as 3 separate doses and administered over a total of 21 hrs. Please refer to the guidelines below for dose preparation based upon patient weight. Dosing for patients who weigh 5 kg to 20 kg ( 2.1 ): Loading Dose : 150 mg/kg diluted in 3 mL/kg of diluent* administered over 1 hr Second Dose : 50 mg/kg diluted in 7 mL/kg of diluent* administered over 4 hrs Third Dose : 100 mg/kg diluted in 14 mL/kg of diluent* administered over 16 hrs Dosing for patients who weigh 21 kg to 40 kg ( 2.1 ): Loading Dose : 150 mg/kg diluted in 100 mL of diluent* administered over 1 hr Second Dose : 50 mg/kg diluted in 250 mL of diluent* administered over 4 hrs Third Dose : 100 mg/kg diluted in 500 mL of diluent* administered over 16 hrs Dosing for patients who weigh 41 kg to 100 kg ( 2.1 ): Loading Dose : 150 mg/kg diluted in 200 mL of diluent* administered over 1 hr Second Dose : 50 mg/kg diluted in 500mL of diluent* administered over 4 hrs Third Dose : 100 mg/kg diluted in 1,000 mL of diluent* administered over 16 hrs * Acetylcysteine Injection is compatible with the following diluents; 5% Dextrose in Water, 0.45% Sodium Chloride Injection, and Sterile Water for Injection Dosing for patients who weigh more than 100 kg ( 2.1 ): No specific studies have been conducted to evaluate the use of or necessity of dosing adjustments in patients weighing over 100 kg. Limited information is available regarding the dosing requirements of patients that weigh more than 100 kg. The dose of Acetylcysteine Injection recommended in these patients should be a loading dose of 15,000 mg infused over one hour followed by a first maintenance dose of 5,000 mg over 4 hrs and a second maintenance dose of 10,000 mg over 16 hrs. 2.1 Administration Instructions (Three-Bag Method: Loading, Second and Third Dose) Dosing for Patients who weigh 5 kg to 20 kg ( Table 1 ): Loading Dose: 150 mg/kg diluted in 3 mL/kg of diluent* administered over 1 hr Second Dose: 50 mg/kg diluted in 7 mL/kg of diluent* administered over 4 hrs Third Dose: 100 mg/kg diluted in 14 mL/kg of diluent* administered over 16 hrs Table 1. Three Bag Method Dosage Guide by Weight in Patients 5 kg to 20 kg Body Weight (kg) Bag 1 (loading dose): 150 mg/kg in 3 mL/kg of diluent Acetylcysteine Injection is compatible with the following diluents; 5% Dextrose in Water, 0.45% Sodium Chloride Injection, and Sterile Water for Injection. infused over 1 hour Bag 2 (second dose): 50 mg/kg in 7mL/kg of diluent infused over 4 hours Bag 3 (third dose): 100 mg/kg diluted in 14 mL/kg of diluent infused over 16...

Side Effects (Adverse Reactions)

6 ADVERSE REACTIONS Most common adverse reactions (incidence >2%) are rash, urticaria/facial flushing and pruritus 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Fresenius Kabi USA, LLC at 1-800-551-7176 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch . 6.1 Clinical Studies Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. In the literature the most frequently reported adverse reactions attributed to intravenous acetylcysteine administration were rash, urticaria and pruritus. The frequency of adverse reactions has been reported to be between 0.2% and 20.8%, and they most commonly occur during the initial loading dose of acetylcysteine. Loading Dose/Infusion Rate Study The incidence of drug-related adverse reactions occurring within the first 2 hours following acetylcysteine administration reported in a randomized study in patients with acetaminophen poisoning is presented in Table 5 by preferred term. In this study patients were randomized to a 15-minute or a 60-minute loading dose regimen. Within the first 2 hours following intravenous acetylcysteine administration, 17% developed an anaphylactoid reaction (18% in the 15-minute treatment group; 14% in the 60-minute treatment group) in this randomized, open-label, multi-center clinical study conducted in Australia to compare the rates of anaphylactoid reactions between two rates of infusion for the intravenous acetylcysteine loading dose [ see Warnings (Section 5 ) and Clinical Studies - Loading Dose/Infusion Rate Study (Section 14 ) ] . Table 5. Incidence of Drug-Related Adverse Reactions Occurring Within the First 2 Hours Following Study Drug Administration by Preferred Term: Loading Dose/Infusion Rate Study Treatment Group 15-min 60-min Number of Patients n=109 n=71 Cardiac disorders 5 (5%) 2 (3%) Severity: Tachycardia NOS Unkn Mild Moderate Severe Unkn Mild Moderate Severe 4 (4%) 1 (1%) 2 (3%) Gastrointestinal disorders 16 (15%) 7 (10%) Severity: Nausea Vomiting NOS Unkn Mild Moderate Severe Unkn Mild Moderate Severe 1(1%) 6 (6%) 1 (1%) 1 (1%) 2 (2%) 11 (10%) 2 (3%) 4 (6%) Immune System Disorders 20 (18%) 10 (14%) Severity: Anaphylactoid reaction Unkn Mild Moderate Severe Unkn Mild Moderate Severe 2(2%) 6 (6%) 11 (10%) 1 (1%) 4 (6%) 5 (7%) 1 (1%) Respiratory, thoracic and mediastinal disorders 2 (2%) 2 (3%) Severity: Pharyngitis Rhinorrhoea Rhonchi Throat tightness Unkn Mild Moderate Severe Unkn Mild Moderate Severe 1 (1%) 1 (1%) 1 (1%) 1 (1%) Skin & subcutaneous tissue disorders 6 (6%) 5 (7%) Severity: Pruritus Rash NOS Unkn Mild Moderate Severe Unkn Mild Moderate Severe 1 (1%) 2 (3%) 3 (3%) 2 (2%) 3 (4%) Vascular disorders 2 (2%) 3 (4%) Severity: Flushing Unkn Mild Moderate Severe Unkn Mild Moderate Severe 1 (1%) 1 (1%) 2 (3%) 1 (1%) Unkn=Unknown Postmarketing Safety Study A large multi-center study was performed in Canada where data were collected from patients who were treated with intravenous acetylcysteine for acetaminophen overdose between 1980 and 2005. This study evaluated 4709 adult cases and 1905 pediatric cases. The incidence of anaphylactoid reactions in adult (overall incidence 7.9%) and pediatric (overall incidence 9.5%) patients is presented in Tables 6 and 7 . Table 6.Distribution of reported reactions in adult patients receiving intravenous acetylcysteine Incidence (%) Reaction % of Patients (n=4709) Urticaria/Facial Flushing 6.1% Pruritus 4.3% Respiratory Symptoms Respiratory symptoms are defined as presence of any of the following: cough, wheezing, stridor, shortness of breath, chest tightness, respiratory distress, or bronchospasm. 1.9% Edema 1.6% Hypotension 0.1% Anaphylaxis 0.1% Table 7 Distribution of reported reactions in pediatric patients receiving intravenous acetylcysteine Incidence (%) Reaction % of Patients...

Drug Interactions

7 DRUG INTERACTIONS No drug-drug interaction studies have been conducted. No drug-drug interaction studies have been conducted ( 7 )

Contraindications

4 CONTRAINDICATIONS Acetylcysteine Injection is contraindicated in patients with previous anaphylactoid reactions to acetylcysteine. Patients with previous anaphylactoid reaction to acetylcysteine ( 4 )

Pregnancy and Breastfeeding

8.1 Pregnancy Pregnancy Category B There are no adequate and well-controlled studies of Acetylcysteine Injection in pregnant women. However, limited case reports of pregnant women exposed to acetylcysteine during various trimesters did not report any adverse maternal, fetal or neonatal outcomes. There are published reports on four pregnant women with acetaminophen toxicity, who were treated with oral or intravenous acetylcysteine at the time of delivery. Acetylcysteine crossed the placenta and was measurable following delivery in serum and cord blood of three viable infants and in cardiac blood of a fourth infant at autopsy (22 weeks gestational age who died 3 hours after birth). No adverse sequelae developed in the three viable infants. All mothers recovered and none of the infants had evidence of acetaminophen poisoning. Reproduction studies were performed in rats at oral doses up to 2,000 mg/kg/day (1.1 times the recommended total human intravenous dose of 300 mg/kg based on body surface area comparison) and in rabbits at oral doses up to 1,000 mg/kg/day (1.1 times the recommended total human intravenous dose of 300 mg/kg based on body surface area comparison). No effects on fertility or harm to the fetus due to acetylcysteine were observed.

8.3 Nursing Mothers It is not known whether Acetylcysteine Injection is present in human milk. Because many drugs are excreted in human milk, caution should be exercised when acetylcysteine is administered to a nursing woman. Based on the pharmacokinetics of acetylcysteine, it should be nearly completely cleared 30 hours after administration. Nursing women may consider resuming nursing 30 hours after administration.

Overdosage

10 OVERDOSAGE Single intravenous doses of acetylcysteine at 1000 mg/kg in mice, 2445 mg/kg in rats, 1500 mg/kg in guinea pigs, 1200 mg/kg in rabbits and 500 mg/kg in dogs were lethal. Symptoms of acute toxicity were ataxia, hypoactivity, labored respiration, cyanosis, loss of righting reflex and convulsions.

How Supplied

16 HOW SUPPLIED/STORAGE AND HANDLING Acetylcysteine Injection is available as a 20% solution (200 mg/mL) in 30 mL single dose glass vials. Each single dose vial contains 6 g/30 mL (200 mg/mL) of Acetylcysteine. Acetylcysteine Injection is sterile and can be used for intravenous administration. Acetylcysteine Injection is available as: Product Code Unit of Sale Strength Each PRX963030 NDC 63323-963-44 Unit of 4 20% (6 grams per 30 mL) (200 mg per mL) NDC 63323-963-41 30 mL Single Dose glass vial Do not use previously opened vials for intravenous administration. Note: The color of Acetylcysteine Injection may turn from essentially colorless to a slight pink or purple once the stopper is punctured. The color change does not affect the quality of the product. The stopper in the Acetylcysteine Injection vial is formulated with a synthetic base-polymer and does not contain Natural Rubber Latex, Dry Natural Rubber, or blends of Natural Rubber. Storage Store unopened vials at controlled room temperature, 20° to 25°C (68° to 77°F) [see USP Controlled Room Temperature].